Although ST 321 had a captain assigned to it, Vader occasionally chose to pilot it himself. He notably did so shortly after the Emperor's arrival at the Death Star, piloting the shuttle down from the battle station to the Imperial base that guarded its shield generator on the Sanctuary Moon. Shortly thereafter, even as a massive battle between the Empire and the enemy Alliance to Restore the Republic took place in orbit, Vader dueled his estranged son, the Alliance hero Luke Skywalker, aboard the Death Star. Ultimately, Vader chose to redeem himself and turned on the Emperor to protect his son, but he was mortally wounded in the process. With the Death Star about to explode, Skywalker then used ST 321 to escape the endangered battle station along with his deceased father.[5]

Upon slipping out of the fast-deteriorating Death Star, Vader's shuttle was almost intercepted by Shara Bey of the Alliance's Green Squadron, who proceeded to cover it from incoming TIE/IN interceptors after identifying its pilot, Luke Skywalker, as a friendly.[7]